The argument started when the male victim was texting during the previews before a showing of Lone Survivor, Nocco said.

"It's absolutely crazy it would rise to this level over somebody just texting," Nocco said.

Charles Cummings, who was in the theater, said Oulson told Reeves he was texting with his 3-year-old daughter.

"Somebody throws popcorn. I'm not sure who threw the popcorn," Cummings said. "And then bang, he was shot."

The victims were airlifted to a Bay area hospital. Investigators describe the shooting as an "isolated incident."

Cobb Theatres issued a statement saying the company was "deeply saddened," adding that "our thoughts and prayers are with the victims and their families." The building was closed and an investigation was underway. "The safety, security and comfort of our guests and team members are always our top priorities, and we are truly heartbroken by this incident," the statement said.

Wesley Chapel, which has a population of about 45,000, is located near Tampa.

In July 2012, 12 people were killed and 70 wounded when a man walked into a movie theater in Aurora, Colo., and started shooting. James Holmes has pleaded not guilty by reason of insanity. His trial is set for August.